1. Field of the Invention
The present invention relates to a liquid crystal projection apparatus mounted on a panel of an over head projector (OHP).
2. Description of the Related Art
FIG. 25 is a view for explaining an engaged state of a conventional liquid crystal projection apparatus. The apparatus is composed of a main body 100 and a remote controller 105. The main body 100 is mounted on a panel of an OHP 101 in use. The OHP 101 comprises a light source provided below the panel on which the main body 100 is mounted, and a projection lens above the panel, and projects the light from the light source on a specified screen 102 through the projection lens. The main body 100 is realized, for example, by a transmissive type liquid crystal display panel, connected to a personal computer 103 through a cable 104, and displays an image on the basis of image signals from the personal computer 103. The image displayed on the main body 100 is magnified and projected on the screen 102 by the OHF 101.
The personal computer 103 is connected a mouse 110 which inputs mouse signals. The personal computer 103 generates an image signal corresponding with a predetermined mouse signal generated by the operator's mouse operation, and the image signal is given to the main body 100 through the cable 104. The mouse 110 is realized, for example, by the below-mentioned mouse, and the image signal is selected by specifying with a cursor, that is, by moving the cursor displayed on display means provided in the personal computer 103 to a desired position by the use of the mouse 110. Namely, the personal computer 103 generates an image signal based on the predetermined processing at the specified position.
The remote controller 105 constituting the conventional liquid crystal projection apparatus comprises a plurality of buttons and keys, through which the adjustment of display conditions such as horizontal/vertical position and density is carried out.
In the case where such the conventional liquid crystal projection apparatus is used for presentation, the change of projected images, namely, the change of images displayed on the main body 100, is carried out by the presenter's operation of the mouse 110 of the personal computer 103, or by another person's operation thereof.
FIG. 26 is a plan view of the mouse 110 of the prior art. FIGS. 27A-27D are output signal diagrams showing a moving direction of the mouse 110 of FIG. 26. FIG. 28A is a view of a pin connection arrangement of a connector 106 which connects the mouse 110 of FIG. 26 with the personal computer 103, and FIG. 28B is a view of pin output signals of the connector 106.
As shown in FIG. 26, the mouse 110 can detect four moving directions in indicated by arrows X1, X2, Y1, Y2. For example, the moving direction and moving amount are detected by detecting which direction and how many units the mouse has rotated, on the basis of unit rotation of a mouse ball 110a which is possessed by the mouse. FIG. 27A, 27B show the waveform of a signal which is detected when the mouse is moved toward a plus direction, namely, X1 or Y1 direction (one direction) by unit length. On the other hand, FIG. 27C, 27D show the wave form of a signal which is detected when the mouse is moved toward a minus direction, namely, X2 or Y2 direction (the other direction) by unit length. The rotation data of the mouse 110 is transmitted to the personal computer 103 through the connector 106, for example, whose pin arrangement is as shown in FIGS. 28A, 28B. A source voltage signal is transmitted from a pin No. 1, the rotation data is transmitted from pins Nos. 2-5, and a select signal from a button and a key provided in the mouse 110 is transmitted from pins Nos. 6-8. A pin No. 9 is grounded.
FIGS. 29A, 29B are a top and a bottom perspective view of a mouse 111 of other type, respectively. The mouse 111 comprises a left switch 112, a middle switch 113, and a right switch 114 for conducting the selection of icons and cells, is provided with a mouse ball 115 on the rear thereof.
FIG. 30 is a plan view of a remote controller 105 of the prior art. The remote controller 105 comprises a plurality of keys 116-120, and a transmitting portion 121. The above-mentioned adjustment of conditions such as horizontal/vertical position and density level adjustment are directed through the plurality of keys 120. For example, when the density adjustment is directed by selecting any one from the plurality of keys 120, the density level adjustment is conducted by using cursor keys 116-119 different from the keys 120. The remote control signals to be transmitted by directing the keys are radio-transmitted from a transmitter 121. The main body 100 comprises a receiver corresponding the transmitter 121, which receives a remote control signal transmitted from the transmitter 121 of the remote controller 105, and adjusts the above-mentioned display conditions on the basis of the received remote signal.
In the following, the operation of the liquid crystal projection apparatus will be described. FIG. 31 is a block diagram showing an electrical configuration of the conventional liquid crystal projection apparatus. The main body 100 of the conventional liquid crystal projection apparatus comprises an input circuit 200, an A/D (analog/digital) conversion circuit 201, a signal converter 202, a MPU (Micro Processing Unit) interface data register 203, a MPU 204, a PLL (Phase-Locked Loop) 205, a memory controller 206, a field memory 207, a LCD (Liquid Crystal Display) controller 208, a LCD unit 209, and a receiver 210. The main body 100 is interconnected to the personal computer 103 via cable 104, an RGB type of cable, that connects to a RGB connector 104b on the main body 100 and a CRT type of connector 104a of the personal computer 103.
The signals inputted from the personal computer 103 through the cable 104 are separated into respective image signals of red (R), green (G), and blue (B) and horizontal (H) and vertical (V) synchronizing signals in the inputted circuit 200. The horizontal/vertical synchronizing signals are supplied to the signal converter 202, and the image signals of R, G, and B are supplied to the signal converter 202 after being converted into digital signals in the A/D conversion circuit 201. The horizontal/vertical synchronizing signals supplied to the signal converter 202 are controlled in timing by the MPU interface data register 203 and then supplied to the MPU 204. The MPU 204 distinguishes the type of the personal computer 103 connected to the main body 100 on the basis of the inputted synchronizing signals. Additionally, the MPU 204 supplies signals for timing adjustment, suitable to the personal computer 103 connected thereto, through the MPU interface data register 203 to the signal converter 202. The PLL 205 is provided for stabilizing the signals for timing adjustment.
The image signals of R, G, and B inputted into the signal converter 202 is inputted into the memory controller 206 and supplied to the field memory 207 on the basis of the signals for timing adjustment inputted to the memory controller 206. The image signals of R, G and B inputted into the field memory 207 are read out on the basis of read out signals prepared in the memory controller 206; inputted into the LCD controller 208; converted to control signals corresponding to the LCD unit 209; and supplied to the LCD unit 209.
Additionally, the remote control signals transmitted from the remote controller 105 are received by the receiver 210 of the main body 100 and supplied to the MPU 204. The MPU 204 converts the remote control signals and thereafter supplies the converted signals to the LCD unit 209 through the MPU interface data register 203, the signal converter 202, the memory controller 206, the field memory 207 and the LCD controller 208.
As described above, when the presenter him (her) self operates the mouse 110 of the personal computer 103, he (she) must conduct key operation while watching display means of the personal computer 103 arranged separately from the screen 102, as well as presentation while watching the screen 102. That is a burden for the presenter.
On the other hand, when the operation is specially carried out by another person, it is difficult to obtain the coincidence of the timing of changing the projection images and the timing of the operator's key operation. That leads to a problem that the presentation does not flow smoothly.
Moreover, there is also a case such that the personal computer 103 is controlled through the main body 100 of the liquid crystal projection apparatus. In this case, although command signals for controlling the personal computer 103 are outputted to the personal computer 103 from the main body 100 on the basis of the key operation of the remote controller 105, it is necessary to prepare a plurality of software programs for creating command signals, because the command signals are different among the types of personal computer. That requires a lot of time and is inconvenient.